Digitally convertible radio

ABSTRACT

A forward link transmitter in a sectored cell includes a baseband processor having traditional baseband signal digital processing circuitry in addition to including a digital hybrid matrix (vector and delay compensated transformation module) whose phase and amplitude (vector) and delay may be adjusted to compensate for downstream errors that are introduced and detected by a feedback circuit. Accordingly, the baseband processor, by monitoring an output of an analog hybrid matrix producing modulated and amplified radio frequency (RF) signals just prior to propagation from an antenna, can determine errors produced by the analog circuitry including the analog hybrid matrix and may compensate for the same by introducing an amplitude, phase and delay adjustment (in the digital domain) into output digital waveform signals to compensate for the error introduced downstream to the baseband processor.

TECHNICAL FIELD OF THE INVENTION

[0001] This invention relates generally to wireless communicationsystems and, more particularly, to radio frequency (RF) transmittersused within radio transceivers of such wireless communication systems.

DESCRIPTION OF RELATED ART

[0002] Communication systems are known to support wireless and wire linecommunications between wireless and/or wire line communication devices.Such communication systems range from national and/or internationalcellular telephone systems to the Internet, to point-to-point in-homewireless networks. Each type of communication system is constructed, andhence operates, in accordance with one or more communication standards.For instance, wireless communication systems may operate in accordancewith one or more standards, including, but not limited to, advancedmobile phone services (AMPS), digital AMPS, global system for mobilecommunications (GSM), code division multiple access (CDMA), universalmobile telephone systems (UMTSs), local multi-point distribution systems(LMDSs), multi-channel-multi-point distribution systems (MMDSs), and/orvariations thereof, including wireless LAN networks such as IEEE 802.11,Bluetooth, etc.

[0003] For direct communications (also known as point-to-pointcommunications), the participating wireless communication devices tunetheir receivers and transmitters to the same channel or channels (e.g.,one of a plurality of radio frequency carriers of the wirelesscommunication system) and communicate over that channel(s). For indirectwireless communications, each wireless communication device communicatesdirectly with an associated base station (e.g., for cellular services)and/or an associated access point (e.g., for an in-home or in-buildingwireless network) via an assigned channel. To complete a communicationconnection between the wireless communication devices, the associatedbase stations and/or associated access points communicate with eachother directly, via a system controller, via a public switched telephonenetwork (PSTN), via the Internet, and/or via some other wide areanetwork.

[0004] As is known by those of average skill in the art, the transmitterincludes a data modulation stage, one or more intermediate frequencystages, and a power amplifier. The data modulation stage converts rawdata into baseband signals in accordance with the particular wirelesscommunication standard. The one or more intermediate frequency stagesmix the baseband signals with one or more local oscillations to produceRF signals. The power amplifier amplifies the RF signals prior totransmission via an antenna.

[0005] Typically, in a sectored cellular network wherein each cell isdivided into three or more cell sectors, each having its ownamplification and transmission circuitry, beam forming antennastypically are used to create a forward link transmission pattern thatfills the cell sector without overlapping in adjacent cell sectors.While one or two amplifiers could be used in a cell having more than twosectors, it is common to use one amplifier per cell sector. One problemthat has been addressed by the prior art is that of amplifier failure inone of the sectors. A pair of N×N hybrid matrices are used in prior art.The first matrix will divide a signal at an input port of the first N×Nhybrid matrix into N equal components, with a taper applied to each ofthe components. The N signals are then applied to N high poweramplifiers, whereafter the amplified signals are fed to a second N×Nhybrid matrix such that the original signal will only appear at one ofthe second N×N hybrid matrix output ports. One benefit of using the N×Nhybrid matrix for this is that each signal is amplified partially byeach of the amplifiers that are operational. Thus, if one amplifier wereto fail, all output signals could be amplified sufficiently fortransmission through all of the cell sectors (though in a degraded modeof operation). In the hybrid matrix amplifier (prior art), the hybridmatrix is fixed so that the degraded mode of operation impacts thesignal-to-noise ratio. Such power sharing further has an advantage inthat each forward link amplifier need not be designed to accommodatemaximum power loads because additional power may be obtained from one ormore other power amplifiers for maximum power requirements (across allthe sectors). Thus, lower cost power amplifiers may be utilized.

[0006]FIG. 1 is a functional block diagram of a prior art cellularnetwork cell having three cell sectors. More specifically, a cell 02includes three cell sectors 04. Approximately in the center of cell 02exists a base station transceiver set (BTS) 06 that includes anamplifier 08 and an antenna 10 for each cell sector 04. FIG. 1 shows theamplifiers 08 and antennas 10 well within its corresponding cell sector04 to show the relationships therefor. It is understood, however, thatthe amplifiers 08 and antennas 10 for the cell sectors 04 are locatedapproximately in the center of cell 02. The antennas 10 are so calledsector antennas that radiate a pattern to fill cell sectors 04 withoutoverlapping into an adjacent cell sector. For a system as shown in FIG.I in which distinct amplifiers are used but in which a hybrid matrix isnot included for power sharing, each of the amplifiers 08 must bedesigned to satisfy maximum power level demands for the sector.

[0007]FIG. 2 is a prior art transmitter that includes a pair of analoghybrid matrices. A baseband radio 14 produces a plurality of digitalwaveform signals to a digital-to-analog conversion module 16 to generatea corresponding plurality of analog signals. The plurality of analogsignals are then up-converted by a plurality of mixers 18 thatup-convert the plurality of analog signals by multiplying the basebandsignals with a local oscillation signal to create output RF signals. Theoutput RF signals are then produced to a first hybrid matrix 20 thatproduces a corresponding number of transformed signals. Morespecifically, if the first hybrid matrix 20 receives signals sig_1,sig_2 and sig_3, it produces three transformed analog signals havingcomponents of all three signals sig_1, sig_2 and sig_3.

[0008] A power amplifier module 22 includes a plurality of poweramplifiers that are coupled to receive the 1^(st), 2^(nd), and 3^(rd)transformed analog output signals from the first hybrid matrix 20 andamplifies them. A second hybrid matrix 24 then receives the 1^(st),2^(nd), and 3^(rd) transformed and amplified signals and recombines themto create amplified versions of sig_1, sig_2, and sig_3 at the secondhybrid matrix 24 outputs. In operation, the second hybrid matrix 24 addsthe signals at the sum port and cancels out signal portions at theoutput ports of the second hybrid matrix 24. To effectively cancelunwanted signal components at the output ports, however, the relativecomponent vector (phase and amplitude) and delay must be as expected. Ifa vector and/or delay error is introduced in or between the first hybridmatrix 20 or the second hybrid matrix 24, then perfect cancellation doesnot occur at the undesired ports and a resulting waveform continues toinclude components of other waveforms. Accordingly, it is desirable toeliminate the effects of introduced relative vector and delay errors.

[0009] While utilizing hybrid matrices are advantageous for thedescribed reasons, including power sharing, hybrid matrices are analogdevices that introduce vector and delay errors in the output RF signal.Accordingly, what is needed is a system that allows for power sharing toachieve the benefits of an analog hybrid matrix amplifier pair but thatproduces output signals with the ability to compensate for vector anddelay errors.

BRIEF SUMMARY OF THE INVENTION

[0010] A base station transmitter in a sectored cell includes a basebandprocessor having traditional baseband digital signal processingcircuitry for transmitting forward link communication signals. Inaddition, the base station transmitter includes a digital signalprocessor that includes modules that form a digital hybrid matrix havinglogic for vector and delay adjustments to compensate for downstreamvector and delay errors that are introduced. Accordingly, the basebandprocessor, by monitoring an output of an analog hybrid matrix producingmodulated and amplified radio frequency (RF) signals just prior topropagation from an antenna, can indirectly determine relative vectorand delay errors produced by the analog hybrid matrix, amplifiers,mixers, up-converters and connection circuitry coupled downstream fromthe digital signal processing circuitry and may compensate for the sameby introducing a vector and delay adjustment (in the digital domain)into output digital waveform signals to compensate for the errorsintroduced downstream to the baseband processor. Thus, an output signalof the analog hybrid matrix after compensation has far less, or perhapseven no, vector (phase and amplitude) or delay errors despite theaddition of these errors from the downstream circuitry mentioned above.

[0011] More specifically, the baseband processor includes a firstprocessing module for generating a plurality of digital waveformsignals, wherein the plurality of digital waveform signals represents acorresponding plurality of RF analog signals that are to be transmittedwithin corresponding cell sectors of a cellular network cell. A secondprocessing module receives the plurality of digital waveform signals toproduce a plurality of transformed digital waveform signals eachcontaining a portion of each of the plurality of digital waveformsignals. The second processing module includes a vector and delaydetection module and a vector and delay compensated transformationmodule. The second processing module includes a vector and delaycompensated transformation module that transforms and modifies thereceived digital waveform signals in phase, amplitude and delay andproduces its output to a third processing module. The output of thesecond processing module is a plurality of transformed digital waveformsignals that compensate for downstream vector and delay errors. Thethird processing module is coupled to receive the outputs of the secondprocessing module and includes a baseband pre-distortion (BBPD) module,that adjusts for amplifier distortion and a peak power reduction (PPR)module that reduces peak power for a given digital waveform signalthereby reducing the peak power demand of the power amplifier withoutsignificant signal degradation. The third processing module produces aplurality of transformed and adjusted digital waveform signals.

[0012] The plurality of transformed and adjusted digital waveformsignals output from the third processing module is then produced to adigital-to-analog conversion module for converting to an analog (analogsignal) domain. A plurality of transformed analog signals produced bythe digital-to-analog conversion module is then produced to anup-conversion module for mixing a local oscillation signal and areup-converted from a baseband frequency, or intermediate frequency (IF)if an IF stage is used, to a radio frequency to produce a plurality oftransformed RF analog signals. At least one power amplifier module iscoupled to receive the plurality of transformed and amplified RF analogsignals to produce a plurality of amplified RF analog signals whereineach of the plurality of amplified RF analog signals corresponds to eachof the plurality of digital waveform signals.

[0013] A hybrid matrix module, which, in the described embodiment of theinvention is an analog hybrid matrix, is coupled to receive theplurality of transformed and amplified RF analog signals to create aplurality of amplified RF analog signals that are to be transmittedwithin corresponding cell sectors of a cellular network cell. Finally,the inventive transmitter includes feedback circuitry coupled to receivethe plurality of RF analog signals and produces a digital representationof the plurality of amplified RF analog signals to the second processingmodule of the baseband processor module (by way of a digital-to-analogconverter). Accordingly, the second processing module is able toindirectly determine relative vector and delay errors produced by theanalog hybrid matrix, amplifiers, mixers, up-converters and connectioncircuitry coupled downstream from the digital signal processingcircuitry and may compensate for the same by introducing a vector anddelay adjustment (in the digital domain) into the plurality oftransformed digital waveform signals to compensate for the errorsintroduced downstream to the baseband processor. The second processingmodule also includes a digital power amplifier failure compensationmodule for adjusting the signals in case of an amplifier failure suchthat power is steered to the required sectors with the best possiblesignal-to-noise ratio (best performance).

[0014] These and other features, aspects and advantages of the presentinvention will be more fully understood when considered with respect tothe following detailed description, appended claims and accompanyingdrawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0015]FIG. 1 is a functional block diagram of a prior art cellularnetwork cell having three cell sectors;

[0016]FIG. 2 is a prior art transmitter that includes a pair of analoghybrid matrices;

[0017]FIG. 3 is a functional block diagram of a radio transmitter formedaccording to one embodiment of the present invention;

[0018]FIG. 4 is a functional block diagram of a radio transmitterillustrating one aspect of the present invention; and

[0019]FIG. 5 is a flow chart illustrating a method for generatingforward link communication signals according to an embodiment of theinvention.

DETAILED DESCRIPTION OF THE INVENTION

[0020]FIG. 3 is a functional block diagram of a radio transmitter formedaccording to one embodiment of the present invention. A basebandprocessor 30 includes a plurality of modules that produce a plurality oftransformed and adjusted digital waveform signals having compensationcomponents that compensate for errors that are introduced downstream.More specifically, a first processing module 32 generates a plurality ofdigital waveform signals, each of which is a digital bit stream thatrepresents an analog radio frequency (RF) signal (i.e., a digitalrepresentation of an “analog” RF signal) that is to be transmitted to acell sector. A second processing module 34 receives the plurality ofdigital waveform signals and produces a plurality of transformed digitalwaveform signals wherein each of the plurality of transformed digitalwaveform signals include digital representations of portions of each ofa plurality of RF analog signals represented by the plurality of digitalwaveform signals produced by the first processing module 32.

[0021] The second processing module 34 includes an indirect vector anddelay detection module 36 and a vector and delay compensatedtransformation module 38. The indirect vector and delay detection module36 uses the amplitude of the signals at the output ports to determinethe degree of summation and cancellation. Based on the degree ofsummation and cancellation, the vector and delay compensatedtransformation module 38 is formed to introduce either one or both of avector and delay component to the plurality of digital waveform signalsby adjusting the vector and delay compensated transformation module 38.A plurality of transformed digital waveform signals produced by thesecond processing module 34 of the baseband processor 30 is thusmodified in amplitude, phase and delay according to detected vector anddelay errors introduced downstream. A third baseband processor 40 thenapplies a number of further processing functions to each of theplurality of transformed digital waveform signals at the output of thesecond processing module 34. The functions include basebandpre-distortion, peak power reduction and a number of filter functions.The baseband processor 30 and, more specifically, the third processingmodule 40, then produces the plurality of transformed and adjusteddigital waveform signals to a digital-to-analog conversion module 46wherein the plurality of transformed and adjusted digital waveformsignals are converted from a digital domain to an analog domain tocreate a plurality of transformed analog signals. The convertedplurality of transformed analog signals are then produced by thedigital-to-analog conversion module 46 to an up-conversion module 48where they are up-converted from a baseband frequency to a radiofrequency (RF) to create a plurality of transformed RF analog signals.

[0022] The plurality of transformed RF analog signals is then producedfrom the up-conversion module 48 to a power amplification module 50wherein the plurality of transformed RF analog signals is amplified tocreate a plurality of transformed and amplified RF analog signals. Theplurality of transformed and amplified RF analog signals is thenproduced by the power amplification module 50 to a hybrid matrix module52.

[0023] The hybrid matrix module 52 receives the plurality of transformedand amplified RF analog signals and produces a plurality of amplified RFanalog signals to the appropriate sum and cancellation ports fortransmission into an appropriate cell sector. Additionally, theplurality of amplified RF analog signals is also coupled to a feedbackloop 54. The feedback loop 54 includes a switching module 56 coupled toreceive and select between each of the plurality of transformed andamplified RF analog signals before the hybrid matrix module 52 and theplurality of amplified RF analog signals after the hybrid matrix module52. The selected output of the switching module 56 is then produced to adown-conversion module 58 where it converts the selected amplified RFanalog signal to a baseband or intermediate frequency. Thedown-converted signal is then produced to an analog-to-digitalconversion module 60 that converts the signal to the digital domain. Thedigitally converted signals are produced by the analog-to-digitalconversion module 60 to the third processing module 40, and morespecifically, to a peak power reduction module 44 and to apre-distortion module 42. Pre-distortion module 42 and peak powerdetection module 44 are operable to compensate for distortion and reducepeak power for a given digital waveform signal, respectively. Thedigitally converted signals are also produced to the indirect vector anddelay detection module 36 of the second processing module 34.

[0024] The indirect vector and delay detection module 36 of the secondprocessing module 34 then determines the degree of error of the sum andcancellation ports relative to desired values. The vector and delaycompensated transformation module 38 of the second processing module 34compensates and adjusts the amplitude, phase and delay of thecorresponding components of the plurality of digital waveform signalsproduced by the first processing module 32, based on the errorsdetermined by the indirect vector and delay detection module 36, byadjusting the vector and delay compensated transformation module 38 tocompensate for the errors introduced downstream from the basebandprocessor 30.

[0025] For example, if the digital signal represents a first amplifiedRF analog signal, and the vector and delay compensated transformationmodule 38 determines that the first amplified RF analog signal from thehybrid matrix module 46 has a component that is lagging by 10 degreesdue to introduced phase errors, then the vector and delay compensatedtransformation module 38 advances the corresponding component in thecorresponding transformed and adjusted digital waveform signal by 10degrees.

[0026] In this example, the phase shift of the component of the firstamplified RF analog signal has been compensated by adding 10 degrees tothe corresponding transformed and adjusted digital waveform signal.Similar compensation may also be made for the other signal components asnecessary. For example, the indirect vector and delay detection module36 is operable to detect vector (phase and amplitude) and delay errorsand to compensate therefor.

[0027]FIG. 4 is a functional block diagram of a radio transmitterillustrating one aspect of the present invention. A baseband processor62 includes a first processing module 32, a second processing module 64and a third processing module 40. First and third processing modules 32and 40 are as described in FIG. 3. Second processing module 64, however,further includes a digital power amplifier failure compensation module66.

[0028] The digital power amplifier failure compensation module 66 is,among other functions, for defining how the configuration of the vectorand delay compensated transformation module 38 will change to compensatefor a condition where one of the paths between the baseband processor 62and a hybrid matrix 74 has failed, giving the best possible systemperformance under the given failure condition.

[0029] Statistically, all three sectors will not be fully loaded andsince power is shared between all the amplifiers, the amplifier size canbe reduced while still achieving the required total power across allsectors. Without power sharing, the amplifier power has to be highenough to handle the fully loaded sector. But, if the sector isunder-loaded, the power of the amplifier power is under-utilized. Thus,power sharing allows the individual amplifier sizes to be reduced. Thepower sharing capability is a result of the transformation process.

[0030] Many of the components of FIG. 3 are shown in FIG. 4.Accordingly, those components will not be described further here in thedescription of FIG. 4. FIG. 4 further illustrates a feedback loop 70that includes a plurality of directional couplers 72 that are connectedbetween the power amplifiers for each branch and hybrid matrix 74, and aplurality of directional couplers 76 that are connected between hybridmatrix 74 and antennas through which RF is propagated. The feedback loop70 further includes a six-way switch 78. In the example of FIG. 4, thesix directional couplers 72 and 76 are coupled to the six-way switch 78(or, alternatively, a multiplexer) that selects one of the six inputsprovided by the six directional couplers 72 and 76 and produces theselected input to a down-conversion module 84.

[0031] The down-conversion module 84 then produces a baseband orintermediate frequency signal to an analog-to-digital converter 82 forconverting the signal to the digital domain for processing and analysisby the baseband processor 62. The six directional couplers 72 and 76,the six-way switch 78, the down-conversion module 84 and theanalog-to-digital converter 82 all are shown here in FIG. 4 as beingpart of the feedback loop 70. The feedback loop 70 produces the selectedsignal to the baseband processor 62 and, more particularly, to thesecond processing module 64 and third processing module 40 (and themodules included therein) for analysis as described herein and forphase, amplitude and delay of the corresponding signals responsivethereto.

[0032]FIG. 5 is a flowchart illustrating a method by a base station forgenerating forward link communication signals according to an embodimentof the invention. Initially, a baseband processor produces a pluralityof transformed and adjusted digital waveform signals where the digitalwaveform signals represent a corresponding plurality of amplified RFanalog signals (step 90). In general, the radio transmitter transmits anamplified RF analog signal to mobile terminals within a cell or cellsector. Because the baseband processor operates in the digital domain,however, it generates a plurality of transformed and adjusted digitalwaveform signals where the digital waveform signals represent acorresponding plurality of amplified RF analog signals that are to betransmitted from antennas within the corresponding cell sectors.

[0033] Thereafter, a digital-to-analog conversion module in the radiotransmitter converts each of the plurality of transformed and adjusteddigital waveform signals from a digital domain to an analog domain toproduce a plurality of transformed analog signals (step 92). Thetransformed analog signals are then up-converted from a basebandfrequency to radio frequency (RF) to produce a plurality of transformedRF analog signals (step 94). The radio transmitter then amplifies theplurality of transformed RF analog signals produced by the up-conversionmodule to produce a plurality of transformed amplified RF analog signals(step 96).

[0034] The hybrid matrix module is coupled to receive the plurality oftransformed amplified RF analog signals and produces amplified RF analogsignals to an antenna for propagation (step 98). Each of the amplifiedRF analog signals only includes components for the amplified RF analogsignal for transmission into a specific cell sector. The transmitterproduces the amplified RF analog signals to an antenna for propagationthrough a cell sector as well as to a feedback loop (step 100). Inaddition to propagating the amplified RF analog signals, the feedbackloop(s) need to be utilized to provide the baseband processor theability to determine what downstream error has been introduced tofacilitate compensation therefore. Accordingly, the invention includesselecting, in a six-way switching module in one embodiment of theinvention, among the plurality of transformed and amplified RF analogsignals prior to the hybrid matrix module and the plurality of amplifiedRF analog signals being produced after the hybrid matrix module andproduce the selected signal to a mixer for down-conversion from RF tobaseband or an intermediate frequency (step 102).

[0035] Thereafter, the amplified RF analog signals are converted to abaseband or intermediate frequency in the described embodiment of theinvention (step 104). The method then includes conversion of thebaseband or intermediate frequency analog signals to the digital domain(step 106). The digital domain signals are then produced to the basebandprocessor and, more particularly, to the second and third processingmodules of the baseband processor (step 108). The baseband processor or,more particularly, the second processing module of the basebandprocessor, then determines an amount and type of error introduceddownstream of the baseband processor (step 110). Finally, the inventionincludes introducing a corresponding compensation into the digitalwaveform signals to compensate for the determined error introduceddownstream from the baseband processor (step 112).

[0036] The invention disclosed herein is susceptible to variousmodifications and alternative forms. Specific embodiments therefore havebeen shown by way of example in the drawings and detailed description.It should be understood that the drawings and detailed descriptionthereto are not intended to limit the invention to the particular formdisclosed, but on the contrary, the invention is to cover allmodifications, equivalents and alternatives falling within the spiritand scope of the present invention as defined by the claims. Forexample, while the described embodiment of the invention has beendiscussed in terms of a 3 by 3 hybrid matrix, the invention specificallyincludes a matrix of any size (N×N).

What is claimed is:
 1. A radio transmitter, comprising: a basebandprocessor for processing digital signals transmitted and received over awireless communication link, which baseband processor produces aplurality of digital waveform signals each representing a correspondingplurality of analog signals: a first processing module for generatingthe plurality of digital waveform signals, wherein each of the pluralityof digital waveform signals represents a corresponding analog signalthat is to be transmitted within corresponding cell sectors of acellular network cell; a second processing module coupled to receive andtransfer the plurality of digital waveform signals to produce acorresponding plurality of transformed digital waveform signals, eachcontaining components of each of the plurality of digital waveformsignals; a third processing module coupled to receive and adjust thetransformed digital waveform signals to compensate for distortion and toadjust peak power to produce a plurality of transformed and adjusteddigital waveform signals; a digital-to-analog conversion module coupledto receive the plurality of transformed and adjusted digital waveformsignals, the digital-to-analog conversion module for converting theplurality of transformed and adjusted digital waveform signals from adigital domain to an analog domain, the digital-to-analog conversionmodule for producing a plurality of transformed analog signals; anup-conversion module for mixing a local oscillation signal with each ofthe plurality of transformed analog signals to up-convert each of theplurality of transformed analog signals from a baseband frequency to aradio frequency to produce a plurality of transformed RF analog signals;at least one power amplifier module coupled to receive the plurality oftransformed RF analog signals to produce a plurality of transformed andamplified RF analog signals wherein the plurality of transformed andamplified RF analog signals each contain analog components of each ofthe plurality of analog signals; a hybrid matrix module coupled toreceive the plurality of transformed and amplified RF analog signals,the hybrid matrix module for separating analog components of theplurality of analog signals found in each of the plurality oftransformed and amplified RF analog signals to create a plurality ofamplified RF analog signals; and feedback circuitry coupled to receivethe plurality of amplified RF analog signals, the feedback circuitryincluding an analog-to-digital conversion module, the feedback circuitryfor producing digital waveform signals to the second processing moduleof the baseband processor.
 2. The radio transmitter of claim 1 whereinthe second processing module detects at least one of vector and delayerrors in an output signal.
 3. The radio transmitter of claim 2 whereinthe second processing module compensates for at least one of vector anddelay errors in an output signal.
 4. The radio transmitter of claim 1wherein the digital waveform signals comprises three digital waveformsignals that represent three corresponding analog signals.
 5. The radiotransmitter of claim 4 wherein the hybrid matrix module comprises ahybrid matrix, which hybrid matrix includes at least three inputs forreceiving the plurality of transformed and amplified RF analog signalswith components of the plurality of analog signals, the hybrid matrixfurther including at least three outputs for producing the plurality ofamplified RF analog signals.
 6. The radio transmitter of claim 1 whereinthe feedback circuitry includes a plurality of directional couplers, oneattached to each output of the hybrid matrix module wherein the outputsof the hybrid matrix module are propagated from an antenna and are alsoconducted back to the baseband processor in a feedback loop.
 7. Theradio transmitter of claim 6 further comprising a six-way switch forselectively coupling signals back into the baseband processor by way ofan analog-to-digital converter, which six-way switch is coupled toreceive each of the plurality of amplified RF analog signals.
 8. A radiotransmitter, comprising: baseband processor means further includingmeans for producing a plurality of transformed digital waveform signalswherein each of the plurality of transformed digital waveform signalsinclude digital representations of portions of each of a plurality ofanalog signals; a digital-to-analog conversion module for convertingeach of the plurality of transformed digital waveform signals from adigital domain to an analog domain; an up-conversion module forconverting a plurality of transformed analog signals produced by thedigital-to-analog conversion module to a radio frequency (RF); a poweramplification module for amplifying a plurality of transformed RF analogsignals produced by the up-conversion module; and a hybrid matrix meansfor producing amplified RF analog signals wherein each of the pluralityof amplified RF analog signals consists of approximately only one analogsignal for transmission into a cell sector.
 9. The radio transmitter ofclaim 8 further including feedback means coupled to receive and producethe plurality of amplified RF analog signals and to the basebandprocessor means by way of an analog-to-digital conversion module. 10.The radio transmitter of claim 9 wherein the feedback means comprises aplurality of directional couplers coupled to receive the plurality ofamplified RF analog signals.
 11. The radio transmitter of claim 8wherein the hybrid matrix means comprises an N×N hybrid matrix wherein“N” is greater than or equal to
 3. 12. A method for generating forwardlink communication signals, comprising: producing, in a basebandprocessor, a plurality of transformed digital waveform signals whereineach of the plurality of transformed digital waveform signals includedigital representations of portions of each of a plurality of analogsignals; converting, in a digital-to-analog conversion module, each ofthe plurality of transformed digital waveform signals from a digitaldomain to an analog domain to create a plurality of transformed analogsignals; converting, in an up-conversion module, the plurality oftransformed analog signals produced by the digital-to-analog conversionmodule from a baseband frequency to create a plurality of transformedradio frequency (RF) analog signals; power amplifying the plurality oftransformed RF analog signals produced by the up-conversion module; andproducing, in a hybrid matrix module, coupled to receive the pluralityof transformed RF analog signals, a plurality of amplified RF analogsignals wherein each of the plurality of amplified RF analog signalsconsists of approximately one analog signal for transmission into a cellsector.
 13. The method of claim 12 further including receiving theplurality of amplified RF analog signals and converting the plurality ofamplified RF analog signals to the digital domain after down-conversionto baseband.
 14. The method of claim 13 further including producing theplurality of amplified RF analog signals converted to the digital domainto the baseband processor.
 15. The method of claim 14 further includingdetermining a vector and delay error of the plurality of amplified RFanalog signals.
 16. The method of claim 15 further including introducinga phase adjustment into the digital representations of each of theplurality of RF analog signals prior to producing a plurality oftransformed and adjusted digital waveform signals to compensate for adetermined phase error.
 17. The method of claim 15 further includingintroducing an amplitude adjustment into the digital representations ofeach of the plurality of RF analog signals prior to producing theplurality of transformed digital waveform signals to compensate for thedetermined phase error.
 18. The method of claim 15 further includingintroducing a delay adjustment into the digital representations of eachof the plurality of RF analog signals prior to producing the pluralityof transformed digital waveform signals to compensate for the determinedphase error.